Windows PowerShell Cookbook

Chapter 13. Tracing and Error Management

13.0. Introduction

What if it doesn’t all go according to plan? This is the core question behind error management in any system and plays a large part in writing PowerShell scripts as well.

While it is a core concern in many systems, PowerShell’s support for error management provides several unique features designed to make your job easier: the primary benefit being a distinction between terminating and nonterminating errors.

When running a complex script or scenario, the last thing you want is for your world to come crashing down because a script can’t open one of the 1,000 files it is operating on. Although it should make you aware of the failure, the script should still continue to the next file. That is an example of a nonterminating error. But what if the script runs out of disk space while running a backup? That should absolutely be an error that causes the script to exit—also known as a terminating error.

Given this helpful distinction, PowerShell provides several features that allow you to manage errors generated by scripts and programs, and also allows you to generate them yourself.

13.1. View the Errors Generated by a Command

Problem

You want to view the errors generated in the current session.

Solution

To access the list of errors generated so far, use the $error variable, as shown by Example 13-1.

Example 13-1. Viewing errors contained in the $error variable

PS >1/0 Attempted to divide by zero. At line:1 char:3 + 1/0 <<<< PS >$error[0] | ...